Dissertation / PhD Thesis/Book

PreJuSER-26980

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Untersuchungen zu einem neuen Isopentenyldiphosphat-Biosyntheseweg in Escherichia coli und Zymomonas mobilis : Identifizierung und Charakterisierung beteiligter Gene

Grolle, S. (Corresponding author)FZJ*

2000
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/20636

Report No.: Juel-3799

Abstract: In the last few years, evidence has emerged that in bacteria a novel biosynthetic pathway to isopentenyl diphosphate exists. In this pathway isopentenyl diphosphate is formed from pyruvate and glyceraldehyde 3-phosphate. In the first reaction step these C4 compounds are combined to 1-deoxyxylulose 5-phosphate synthase was identified in $\textit{E. coli}$ by searching for transketolase-homologous genes. The corresponding gene product was purified and was shown by NMR analysis to catalyze in a thiamin diphosphate (TPP) and Mg$^{2}$ dependent reaction the synthesis of 1-deoxyxylulose 5-phosphate. Phylogenetic investigation revealed that the 1-deoxyxylulose 5-phosphate synthase belongs to a new family of TPP dependent enzymes. The $\textit{dxs}$ gene is located at 9 min on the $\textit{E. coli}$ chromosome and is organized in one operon with a putative aldoketo-reductase gene. The disruption of this $\textit{E. coli}$ gene yielded no phenotype which indicates that the gene is not involved in the novel pathway. The gene encoding the second enzyme of the pathway, the 1-deoxyxylulose 5-phosphate reductoisomerase, was isolated from $\textit{Z. mobilis}$. The 1-deoxyxylulose 4-phosphate reductoisomerase catalyzes the NADPH and Mn$^{2}$ dependent rearrangement and subsequent reduction of 1-deoxyxylulose 5-phosphate to 2C-methylerythritol 4-phosphate. The enzyme activity is competitively inhibited by the antibiotic fosmidomycin with a K$_{i}$ of 0,6 $\mu$M. By using a $\textit{E. coli}$ strain engineered to produce the isoprenoide zeaxanthin the gene encoding IPP-isomerase, but no further genes of the novel pathway could be isolated from an $\textit{E. coli}$ expression gene library.

Note: Record converted from VDB: 12.11.2012
Note: Düsseldorf, Univ., Diss., 2000

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Contributing Institute(s):

1. Institut für Biotechnologie (IBT)

Research Program(s):

1. Mikrobiologische Grundlagen der Gewinnung von Proteinen (41.35.1)

Appears in the scientific report 2000

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Database coverage:

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